I am probably missing something obvious, but what are you mulching and why is it important to wait for the ground to be frozen? It seems many people mulch in spring, but this is mainly for looks. Nature "self mulches" in the fall which leads me to believe this is generally the best time.

In the winter, I usually put mulch of pine boughs down over some or my more tender plants. I wait until the ground is frozen because if you don't, you will likely have everything eaten by voles/mice. What I am trying to prevent, primarily, is the heave which takes place with freezing and thawing.

Since I was planting way later than I should have been (mind you PLANTING perennials) since I broke my foot in August, this is especially important to make sure that my plants make it through the winter. I moved here from Connecticut, and therefore, I am unsure as to when some of the things should be done here. I was soundly zone 6 there, and I'm 5/borderline 6 here. It has been a long time since I lived in Michigan and I really can't remember what's best.

If I "self mulched" as fall does, I would end up losing stuff which I want to try to prevent.